Lasers have become useful in a number of applications. For example, lasers may be used in optical communications to transmit digital data across a fiber optic network. The laser may be modulated by a modulation signal, such as an electronic digital signal, to produce an optical signal transmitted on a fiber optic cable. An optically sensitive device, such as a photodiode, is used to convert the optical signal to an electronic digital signal transmitted through the fiber optic network. Such fiber optic networks enable modern computing devices to communicate at high speeds and over long distances.
One component included in many optical transmitters is a distributed Bragg reflector (“DBR” or “DBR mirror”). A DBR is a reflector formed from multiple layers of alternating materials with varying refractive index, or by periodic variation of some characteristic (such as height) of a dielectric waveguide, resulting in periodic variation in the effective refractive index through the DBR. Each layer boundary may cause a partial reflection of an optical wave. DBRs may be included in some edge-emitting lasers, such as DBR lasers.
In various industries, bitrates for data transmission per channel have surpassed 100 gigabit per second (Gb/s), establishing transmitter performance exceeding 60 gigahertz (GHz) bandwidth (BW) as an industry goal for the 100 Gb/s non-return-to zero (NRZ) format. Although some electro absorption modulators have exhibited the capability to approach 60 GHz BW, the BW of Mach-Zehnder modulators and directly modulated lasers (DML) have lagged behind at approximately 30 GHz.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.